<template>
  <div class="course">
    <Header></Header>
    <div class="top-bar"></div>
    <div style="background-color: #f6f6f6;">
      <div class="main">
        <!-- 筛选条件 -->
        <div class="condition">
          <ul class="cate-list">
            <li class="title">课程分类:</li>
            <li @click="category=0" :class="{this:category===0}">全部</li>
            <li @click="category=value.id" :class="{this:category===value.id}" v-for="(value, index) in category_list"
                :key="value.id">{{value.name}}
            </li>
          </ul>

          <div class="ordering">
            <ul>
              <li class="title">筛&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;选:</li>
              <li class="default" @click="change_order_type('id')" :class="change_order_class('id')">默认</li>
              <li class="hot" @click="change_order_type('students')" :class="change_order_class('students')">人气</li>
              <li class="price" @click="change_order_type('price')" :class="change_order_class('price')">价格</li>
            </ul>
            <p class="condition-result">共21个课程</p>
          </div>

        </div>
        <!-- 课程列表 -->
        <div class="course-list">
          <div v-for="(value, index) in course_list" :key="value.id" class="course-item">
            <div class="course-image">
              <img :src="value.course_img" alt="">
            </div>
            <div class="course-info">
              <h3>
                <router-link :to="'/fighting/detail/'+value.id+'/'">{{value.name}}</router-link>
                <span><img src="/static/image/avatar1.svg" alt="">{{value.students}}人已加入学习</span></h3>
              <p class="teather-info">{{value.teacher.name}} {{value.teacher.signature}} {{value.teacher.title}}<span>共{{value.lessons}}课时/{{value.lessons===value.pub_lessons?'更新完成':`已更新${value.pub_lessons}课时`}}</span>
              </p>
              <ul class="lesson-list">
                <li v-for="(item, i) in value.lesson_list"><span class="lesson-title">0{{i+1}}| 第{{item.lesson}}节：{{item.name}}</span>
                  <span class="free" v-if="item.free_trail">免费</span></li>
              </ul>
              <div class="pay-box">
                <span class="discount-type" v-if="value.discount_name">{{value.discount_name}}</span>
                <span class="discount-price">￥{{value.real_price}}</span>
                <span class="original-price" v-if="value.discount_name">原价：{{value.price}}元</span>
                <span class="buy-now">立即购买</span>
              </div>
            </div>
          </div>
        </div>
      </div>

      <!--   @current-change="handleCurrentChange" 即element-ui封装好的监听当前页码数变化的函数     -->
      <!--   @size-change="handleSizeChange" 即element-ui封装好的监听当前页面显示多少条数据的函数   -->
      <el-pagination
        background
        layout="prev, pager, next, sizes"
        @current-change="handleCurrentChange"
        :page-size="filters.size"
        @size-change="handleSizeChange"
        :page-sizes="[2,3,5,10]"
        :total="total">
      </el-pagination>
    </div>

    <Footer></Footer>
  </div>
</template>

<script>
    import Header from "./common/Header"
    import Footer from "./common/Footer"

    export default {
        name: "Fighting",
        data() {
            return {
                category: 0,             // 标记哪个课程分类被选中的，默认选中'全部'
                category_list: [],      // 存放课程分类信息
                total: 0,               // 总数据量
                filters: {
                    type: 'id',        // 标记当前选中的是那种排序状态（按默认、人气、价格）
                    orders: 'asc',    // 标记当前某种排序状态的排序方式（按升序、降序）
                    page: 1,          // 当前用户点击的页码
                    size: 5,          // 每页所显示的数据量
                },
                course_list: [],
            }
        },
        components: {
            Header,
            Footer,
        },
        watch: {                   // 监听 'category' 这个属性，一旦发生变化就会触发对应的函数
            category() {
                this.get_course();
            }
        },

        created() {
            this.get_category();
            this.get_course();
        },

        methods: {
            // 获取课程分类
            get_category() {
                this.$axios.get(`${this.$settings.Host}/course/category`)
                    .then((res) => {
                        this.category_list = res.data;
                    })
                    .catch((error) => {
                        console.log(error.response);
                    })
            },

            // 点击切换排序状态的选中状态（返回选中状态的类属性'this'以及排序方式'asc/desc'）
            change_order_class(type) {
                if (type === this.filters.type && this.filters.orders === 'asc') {
                    return 'this desc';
                } else if (type === this.filters.type && this.filters.orders === 'desc') {
                    return 'this asc';
                } else {
                    return '';
                }
            },

            // 点击切换排序方式（升序/降序）
            change_order_type(type) {
                if (this.filters.type === type && this.filters.orders === 'asc') {
                    this.filters.orders = 'desc'
                } else if (this.filters.type === type && this.filters.orders === 'desc') {
                    this.filters.orders = 'asc'
                }
                this.filters.type = type;

                // 点击切换排序方式时，触发获取课程的接口
                this.get_course();
            },

            // 获取课程相关信息
            get_course() {
                let filters = {
                    // page 即路由中携带给后台?page=2即显示第二页的数据
                    page: this.filters.page,
                    // size 即路由中携带给后台?size=5即每页显示5条数据
                    size: this.filters.size,
                };

                if (this.category > 0) {
                    filters.course_category = this.category;
                }

                if (this.filters.orders === 'desc') {
                    filters.ordering = '-' + this.filters.type;
                } else {
                    filters.ordering = this.filters.type;
                }

                this.$axios.get(`${this.$settings.Host}/course/list`,
                    {
                        params: filters,
                    })
                    .then((res) => {
                        let data = res.data;
                        this.course_list = res.data.results;
                        this.total = data.count;
                    })
                    .catch((error) => {
                        console.log(error.reponse);
                    })
            },

            // 监听当前页码数的变化
            handleCurrentChange(page) {
                this.filters.page = page;
                this.get_course();
            },

            // 监听当前页面显示多少条数据
            handleSizeChange(size) {
                this.filters.size = size;
                this.get_course();
            }
        },
    }
</script>


<style scoped>
  .course .top-bar {
    height: 35px;
    background-color: #f6f6f6;
  }

  .course .footer-bar {
    height: 1px;
    background-color: #f6f6f6;
  }

  .course .main {
    width: 1100px;
    margin: 0 auto 0;
  }

  .course .condition {
    margin-bottom: 35px;
    padding: 25px 30px 25px 20px;
    background: #fff;
    border-radius: 4px;
    box-shadow: 0 2px 4px 0 #f0f0f0;
  }

  .course .cate-list {
    border-bottom: 1px solid #333;
    border-bottom-color: rgba(51, 51, 51, .05);
    padding-bottom: 18px;
    margin-bottom: 17px;
  }

  .course .cate-list::after {
    content: "";
    display: block;
    clear: both;
  }

  .course .cate-list li {
    float: left;
    font-size: 16px;
    padding: 6px 15px;
    line-height: 16px;
    margin-left: 14px;
    position: relative;
    transition: all .3s ease;
    cursor: pointer;
    color: #4a4a4a;
    border: 1px solid transparent; /* transparent 透明 */
  }

  .course .cate-list .title {
    color: #888;
    margin-left: 0;
    letter-spacing: .36px;
    padding: 0;
    line-height: 28px;
  }

  .course .cate-list .this {
    color: #ffc210;
    border: 1px solid #ffc210 !important;
    border-radius: 30px;
  }

  .course .ordering::after {
    content: "";
    display: block;
    clear: both;
  }

  .course .ordering ul {
    float: left;
  }

  .course .ordering ul::after {
    content: "";
    display: block;
    clear: both;
  }

  .course .ordering .condition-result {
    float: right;
    font-size: 14px;
    color: #9b9b9b;
    line-height: 28px;
  }

  .course .ordering ul li {
    float: left;
    padding: 6px 15px;
    line-height: 16px;
    margin-left: 14px;
    position: relative;
    transition: all .3s ease;
    cursor: pointer;
    color: #4a4a4a;
  }

  .course .ordering .title {
    font-size: 16px;
    color: #888;
    letter-spacing: .36px;
    margin-left: 0;
    padding: 0;
    line-height: 28px;
  }

  .course .ordering .this {
    color: #ffc210;
  }

  .course .ordering .price {
    position: relative;
  }

  .course .ordering .this::before,
  .course .ordering .this::after {
    cursor: pointer;
    content: "";
    display: block;
    width: 0px;
    height: 0px;
    border: 5px solid transparent;
    position: absolute;
    right: 0;
  }

  .course .ordering .this::before {
    border-bottom: 5px solid #aaa;
    margin-bottom: 2px;
    top: 2px;
  }

  .course .ordering .this::after {
    border-top: 5px solid #aaa;
    bottom: 2px;
  }

  .course .ordering .desc::before {
    border-bottom: 5px solid #f5a623;
  }


  .course .ordering .asc::after {
    border-top: 5px solid #f5a623;
  }

  .course .course-item:hover {
    box-shadow: 4px 6px 16px rgba(0, 0, 0, .5);
  }

  .course .course-item {
    width: 1050px;
    background: #fff;
    padding: 0 30px 20px 20px;
    margin-bottom: 35px;
    border-radius: 2px;
    cursor: pointer;
    box-shadow: 2px 3px 16px rgba(0, 0, 0, .1);
    /* css3.0 过渡动画 hover 事件操作 */
    transition: all .2s ease;
  }

  .course .course-item::after {
    content: "";
    display: block;
    clear: both;
  }

  /* 顶级元素 父级元素  当前元素{} */
  .course .course-item .course-image {
    float: left;
    width: 423px;
    height: 210px;
    margin-right: 30px;
    margin-top: 27px;
  }

  .course .course-item .course-image img {
    width: 100%;
  }

  .course .course-item .course-info {
    float: left;
    width: 596px;
  }

  .course-item .course-info h3 {
    font-size: 26px;
    color: #333;
    font-weight: normal;
    margin-bottom: 8px;
  }

  .course-item .course-info h3 span {
    font-size: 14px;
    color: #9b9b9b;
    float: right;
    margin-top: 14px;
  }

  .course-item .course-info h3 span img {
    width: 11px;
    height: auto;
    margin-right: 7px;
  }

  .course-item .course-info .teather-info {
    font-size: 14px;
    color: #9b9b9b;
    margin-bottom: 14px;
    padding-bottom: 14px;
    border-bottom: 1px solid #333;
    border-bottom-color: rgba(51, 51, 51, .05);
  }

  .course-item .course-info .teather-info span {
    float: right;
  }

  .course-item .lesson-list::after {
    content: "";
    display: block;
    clear: both;
  }

  .course-item .lesson-list li {
    float: left;
    width: 44%;
    font-size: 15px;
    color: #666;
    padding-left: 25px;
    /* background: url("路径") 是否平铺 x轴位置 y轴位置 */
    background: url("/static/image/play-icon-gray.svg") no-repeat left 4px top 2px;
    margin-bottom: 15px;
  }

  .course-item .lesson-list li .lesson-title {
    /* 以下3句，文本内容过多，会自动隐藏，并显示省略符号 */
    text-overflow: ellipsis;
    overflow: hidden;
    white-space: nowrap;
    display: inline-block;
    max-width: 200px;
  }

  .course-item .lesson-list li:hover {
    background-image: url("/static/image/play-icon-yellow.svg");
    color: #ffc210;
  }

  .course-item .lesson-list li .free {
    width: 34px;
    height: 20px;
    color: #fd7b4d;
    vertical-align: super;
    margin-left: 10px;
    border: 1px solid #fd7b4d;
    border-radius: 2px;
    text-align: center;
    font-size: 10px;
    white-space: nowrap;
  }

  .course-item .lesson-list li:hover .free {
    color: #ffc210;
    border-color: #ffc210;
  }

  .course-item .pay-box::after {
    content: "";
    display: block;
    clear: both;
  }

  .course-item .pay-box .discount-type {
    padding: 6px 10px;
    font-size: 17px;
    color: #fff;
    text-align: center;
    margin-right: 8px;
    background: #fa6240;
    border: 1px solid #fa6240;
    border-radius: 10px 0 10px 0;
    float: left;
  }

  .course-item .pay-box .discount-price {
    font-size: 25px;
    color: #fa6240;
    float: left;
  }

  .course-item .pay-box .original-price {
    text-decoration: line-through;
    font-size: 14px;
    color: #9b9b9b;
    margin-left: 10px;
    float: left;
    margin-top: 10px;
  }

  .course-item .pay-box .buy-now {
    width: 120px;
    height: 35px;
    background: transparent;
    color: #fa6240;
    font-size: 16px;
    border: 1px solid #fd7b4d;
    border-radius: 3px;
    transition: all .2s ease-in-out;
    float: right;
    text-align: center;
    line-height: 38px;
  }

  .course-item .pay-box .buy-now:hover {
    color: #fff;
    background: #ffc210;
    border: 1px solid #ffc210;
  }
</style>

